523681813 has 2 divisors, whose sum is σ = 523681814. Its totient is φ = 523681812.

The previous prime is 523681811. The next prime is 523681867. The reversal of 523681813 is 318186325.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 357323409 + 166358404 = 18903^2 + 12898^2 .

It is a cyclic number.

It is not a de Polignac number, because 523681813 - 2¹ = 523681811 is a prime.

Together with 523681811, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (523681811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 261840906 + 261840907.

It is an arithmetic number, because the mean of its divisors is an integer number (261840907).

Almost surely, 2^523681813 is an apocalyptic number.

It is an amenable number.

523681813 is a deficient number, since it is larger than the sum of its proper divisors (1).

523681813 is an equidigital number, since it uses as much as digits as its factorization.

523681813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34560, while the sum is 37.

The square root of 523681813 is about 22884.0951973199. The cubic root of 523681813 is about 806.0385823243.

The spelling of 523681813 in words is "five hundred twenty-three million, six hundred eighty-one thousand, eight hundred thirteen".